class Shape {
    public void draw() {
        System.out.println("打印图形");
    }
}
class Circle extends Shape {
    public void draw() {
        System.out.println("⚪");
    }
}
class Triangle extends Shape {
    public void draw() {
        System.out.println("▲");
    }
}
public class Test1 {
    public static void draw1(Shape shape) {
        shape.draw();
    }
    public static void main(String[] args) {
        draw1(new Circle());
        draw1(new Triangle());
    }
}
